90 MESSRS ROBINSON AND KLOSS ON 



Claws much curved, hind claw lonf^cr than inner . . . . . . 13 



Claws straight, hind claw shorter than inner . . Ictiiiai'tus malaycn'iis. 



Primaries exceeding secondaries bj' more than length of tarsus . . . . 14 



Primaries exceeding secondaries by less than length of tarsus . . . . 15 



No elongate occipital crest .. .. .. J(jiiila ninculatn. 



An elongate occipital crest . . . . . . LojjJiotriorchis licneri. 



No elongate crest .. .. .. Siiizii'tii.s cirrJintus Uiini'tefns. 



An elongate crest . . . . . • . • • • . . 16 



Larger ; wing exceeding ] 6 inches .. .. Sinz'tl'tus nijnlensis. 



Smaller; wing less than 14 inches . . . . SpizacUts nlhnnigcr. 



Tarsi reticulated; scutellae broader than high .. .. ..18 



Tarsi with sonic scutellae broader than high . . . . . . 22 



Tarsi more than ^ length of bill from gape . . . . . . . . 19 



Tarsi iess than ^ length of bill from gape . . Elanus C(Cruh'Hs cccruleus. 



Scales in front of tarsus the same size as those behind . . . . . . 20 



Scales in front of tarsus larger than those behind . . Butastur i7idicus. 



Not crested . . . . . . . . Circactus rjallicus. 



Crested .. .. .. .. .. ..21 



Wing always exceeding 16 inches . . Spilornis chcela rutherfordi. 



Wing never exceeding 16 inches . . Spilornis cJicela bassus. 



Scales beneath toes rough and pointed . . . . . . . . 23 



Scales beneath toes not rough and pointed .. .. .. ..25 



Breast in adults grey ; claws rounded beneath . . . . . . 24 



Breast in adults white; claws grooved beneath . . Ilaliaetas leiicogaster. 



Size large ; wing exceeding 17 inches . . Polioaetus ichtlnjn'etus. 



Size small ; wing less than 17 inches . . I'ulioai'tus huimlis humilis. 



Size moderate ; wing over 12 inches . . . . . . . . 26 



Size smaller ; wing under 11 inches . . . . . . . . 31 



Tarsus short . . . . . . . . . . • . . 27 



Tarsus long . . . . . . . . . . . . 29 



Tail rounded .. .. .. Haliastnr indus intcniicdius. 



Tail forked . . . . . . . . . . . . 28 



Larger; a conspicuous white patch beneath wing . . Milvus melnnotis. 

 Smaller ; no conspicuous white patch beneath wing Milvus migrans govinda. 



Bill from cere to tip less than 0"75 inch . . . . Circus mclanoleiicus. 



Bill from cere to tip more than 0'75 inch . . . . . . . . 30 



Abdomen paler . . . . . . . . Circus spilonotus. 



Abdomen darker . . . . . . Circus ceruginosus aruglnosus. 



Crested .. .. Lopliospizias trivirgatus rufitinctus. 



Not crested . . . . . , , . . . ' . . 32 



Tarsus and toes thick ; middle toe short . . . . . . . . 33 



Tarsus and toes slender; middle toe elongate . . . . • . . 34 



Upper parts pale grey, beneath banded 



in adults-; larger .. .. .. . . Astur badius poliopsis. 



Upper parts dark blackish grey, 



beneath uniform in adults ; smaller . . . . Astur soloensis. 



JOURN. NAT. HIST. SOC. SIAM. 



